<?php
/**
 * @link http://bakery.cakephp.org/articles/view/recaptcha-component-helper-for-cakephp
 */
class RecaptchaHelper extends AppHelper {
    var $helpers = array('form'); 
    
    function display_form($output_method = 'return', $error = null, $use_ssl = false){
        $data = $this->__form(Configure::read("Recaptcha.pubKey"),$error,$use_ssl);
        if($output_method == "echo")
            echo $data;
        else
            return $data;
    }
    
    function hide_mail($email = '',$output_method = 'return'){
        $data = $this->recaptcha_mailhide_html(Configure::read('Recaptcha.pubKey'), Configure::read('Recaptcha.privateKey'), $email);
        if($output_method == "echo")
            echo $data;
        else
            return $data;
    }
    
    /**
     * Gets the challenge HTML (javascript and non-javascript version).
     * This is called from the browser, and the resulting reCAPTCHA HTML widget
     * is embedded within the HTML form it was called from.
     * @param string $pubkey A public key for reCAPTCHA
     * @param string $error The error given by reCAPTCHA (optional, default is null)
     * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)
    
     * @return string - The HTML to be embedded in the user's form.
     */
    function __form($pubkey, $error = null, $use_ssl = false){
        if ($pubkey == null || $pubkey == '') {
            die ("To use reCAPTCHA you must get an API key from <a href='http://recaptcha.net/api/getkey'>http://recaptcha.net/api/getkey</a>");
        }
        
        if ($use_ssl) {
                    $server = Configure::read('Recaptcha.apiSecureServer');
            } else {
                    $server = Configure::read('Recaptcha.apiServer');
            }
    
            $errorpart = "";
            if ($error) {
               $errorpart = "&amp;error=" . $error;
            }
            return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>
    
        <noscript>
              <iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>
                  <textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
                <input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
              <input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
        </noscript>';
    }

    /* Mailhide related code */
    function _recaptcha_aes_encrypt($val,$ky) {
        if (! function_exists ("mcrypt_encrypt")) {
            die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.");
        }
        $mode=MCRYPT_MODE_CBC;   
        $enc=MCRYPT_RIJNDAEL_128;
        $val=$this->_recaptcha_aes_pad($val);
        return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
    }
    
    function _recaptcha_mailhide_urlbase64 ($x) {
        return strtr(base64_encode ($x), '+/', '-_');
    }
    
    /* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
    function recaptcha_mailhide_url($pubkey, $privkey, $email) {
        if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) {
            die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
                 "you can do so at <a href='http://mailhide.recaptcha.net/apikey'>http://mailhide.recaptcha.net/apikey</a>");
        }
        
    
        $ky = pack('H*', $privkey);
        $cryptmail = $this->_recaptcha_aes_encrypt ($email, $ky);
        
        return "http://mailhide.recaptcha.net/d?k=" . $pubkey . "&c=" . $this->_recaptcha_mailhide_urlbase64 ($cryptmail);
    }
    
    /**
     * gets the parts of the email to expose to the user.
     * eg, given johndoe@example,com return ["john", "example.com"].
     * the email is then displayed as john...@example.com
     */
    function _recaptcha_mailhide_email_parts ($email) {
        $arr = preg_split("/@/", $email );
    
        if (strlen ($arr[0]) <= 4) {
            $arr[0] = substr ($arr[0], 0, 1);
        } else if (strlen ($arr[0]) <= 6) {
            $arr[0] = substr ($arr[0], 0, 3);
        } else {
            $arr[0] = substr ($arr[0], 0, 4);
        }
        return $arr;
    }
    
    /**
     * Gets html to display an email address given a public an private key.
     * to get a key, go to:
     *
     * http://mailhide.recaptcha.net/apikey
     */
    function recaptcha_mailhide_html($pubkey, $privkey, $email) {
        $emailparts = $this->_recaptcha_mailhide_email_parts ($email);
        $url = $this->recaptcha_mailhide_url ($pubkey, $privkey, $email);
        
        return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
            "' onclick=\"window.open('" . htmlentities ($url) . "', '', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=500,height=300'); return false;\" title=\"Reveal this e-mail address\">...</a>@" . htmlentities ($emailparts [1]);
    
    }
        

}
?>